EUV startup in talks with ASML, seeks $5 million

LONDON – Extreme ultraviolet light source startup Zplasma Inc. (Seattle, Wash.) is in talks with a number of companies in the EUV lithography sector, including light source suppliers and leading lithography equipment maker ASML, as it seeks $5 million in venture capital or strategic corporate investment.

The company wants the money to develop a prototype source module that can supply 200 watts at the intermediate focus of a EUV lithography scanner. This should allow a throughout of 125 wafers per hour. Making powerful sources of 13.5 nanometer wavelength light are one of the major problems holding back the introduction of EUV lithography and potentially holding back continued miniaturization in the semiconductor industry.

Henry Berg, CEO of Zplasma, told EE Times in email: "Our goal is to have a prototype integrated into an ASML scanner two years from when work is started."

"We want to focus on making the core EUV light-producing module, so we may end up working in conjunction with Cymer, Xtreme and Gigaphoton, not necessarily competing with them," Berg added in the email correspondence. Berg said that Zplasma is holding discussions with Ushio, parent of Xtreme, and Gigaphoton as well as with lithography equipment vendor ASML Holding NV (Veldhoven, The Netherlands).

Zplasma, a spin-off from a University of Washington laboratory that has been working on nuclear fusion plasma constainment reckons it has learned some lessons applicable to a xenon plasma for generating EUV light in a controlled manner (see: Nuclear fusion research aids EUV source breakthrough).

Click on image to enlarge.

Zplasma prototype xenon plasma system. Source: Zplasma

The company already has a prototype that produces a "Z-pinch" plasma region 3 millimeters long by 1-millimeter in diameter.

"The plasma is generated using xenon gas and our patented flow-stabilized Z-pinch. Plasma is generated and accelerated, then assembles into a Z-pinch which is stable, lasting microseconds instead of nanoseconds. This means that each EUV pulse is longer and puts out more power. Critically, the stable end of our pinch also means it does not produce high-energy debris, which can damage the collection optics. Our current prototype was built to prove out the technology. Our product design goal is to run at 5000 hertz and when integrated into a stepper deliver 200 watts of EUV light to the stepper's intermediate focus," Berg told EE Times in his email.

Berg added: "By stretching the length of each discharge pulse, we are increasing the average EUV power produced. This allows us to decrease the instantaneous power, and reduce the operating frequency, thus simplifying the design of both the cooling system and power supply."

However, as integration with ASML could take two years from when the work starts, waiting for Zplasma could make EUV lithography as a volume production technique even later to the party than it already is. Delivery of several NXE:3300 production EUV lithography machines from ASML at a cost of more than $100 million each is expected this year for use in production, in 2013 albeit with lower power sources at around the 50-watt mark.

"The actual integration timeline is totally dependent on who is doing
the stepper integration work, which is undetermined at present. If we
get enough help and cooperation, it could go a lot faster," said Berg.

The Zplasma Z-pinch method can be used with different gases to produce light at different wavelengths. "While our current focus is on 13.5-nm EUV, it is quite possible that our product could be used to produce 6.7 or 6.X nanometer light," Berg said.